When you want to sell or give away your iPhone 5S for the coming iPhone 6, you must remove all your personal information on it. Here is a video about permanently erasing deleted files, clearing browsing history, caches and then you can protect personal data on iPhone 5S.
Watch Video Tutorial:
> Permanently Wipe All Data and Settings from iPhone, iPad & iPod
> Erase Deleted Files: Pictures, Videos, Calls, SMS. Making Them Unrecoverable
> Free Up Valuable Space By Cleaning iDevice of Invalid Files, Cache files & More